Speed governor for injection internal combustion engines



May 30, 1939. A-. SCHWEIZER 2,160,109

SPEED GOVERNOR FOR INJECTION INTERNAL COMBUSTION ENGINES Filed Feb. 8, 1937 ret sted tin -so, tees nits sires.

italirs nevi-cs srnnn GOVERNOR FOR mmorrofi mrnaNAL COMBUSTION ENGINES Alfred Schweizcr, Stuttgart, Germany, assign to Robert Bosch Gesellschait mit besohrinkter Haftung Application February 8, 1937, Serial No. 124,757 Y In Germany February 8, 1936 I h Claims. (Cl. 123- -140) The invention relates to an apparatus iorgo'vernins thespeed of "injection internal combustion engines by means of a governing member, which moves the delivery-amount adjusting a member of the injection pump, and whiohis' moved, in opposition to a returning force, by a governing force produced by a pneumatic pressure head which varies with the speed of the engine, and is influenced by the voluntary adl'u justment of a throttle member controlling the air supply to the engine.

In such apparatus the pneumatic governing pressure determining the variation of the head of pressure, and thus the governing force, rep-- ifi resents a mean value of the strokes produced by the individual pistons of the engine. This pressure may greatly vary when the engine is running under partial load, and especially when running idle, because then a fairly uniform avergo age pressure is not maintained in the induction pipe, as at high speeds, but because in the lower range oi speeds the individual suction strokes make themselves perceptible. The pressure head and thus the governing force thus causes oscil- 2 latory movements to and ire of the governing member, which otherwise quietly remains in a.

definite governing position. These movements are transmitted to thedelivery-amount adjusting member, and may cause an irregular running so of the engine.

an exact adjustment of the running of the engine, for instance, to a definite low idling speed. They require a wide separation of the idling speed range from the minimum speed necessary 35 for just keeping the engine running. The undesirable action of the great variations of pressure might be counteracted, for example. by 'increasing the return force but by doing so the sensitivity of the governing, which must exit 4 more especially in the full load speed range so that the governor may still respond even to a small pressure head, would sufler.

The object of the invention consists in the .feature, that in the air passage leading to the r 45 engine cylinders supplementary means'areprovlded, which by the supply of additional air,

quickly bring the pneumatic head of pressure, when this fluctuates especially when :the load I and engine speed is low, owing to the individual 60, suction-strokes which then make themselves perceptible and thereby sets the governing member in oscillation, to the mean value corresponding to the adjusted governing condition, and maintain it at this, whereby the oscillations of the an governing member are damped.

Such governors renderdimcult' Some eramples of construction of the invention are shown in the accompanying drawing,

Figure l is a. section through the governing apparatus of an injection pump with an exam- 5 'ple of the arrangement of the engine induction pipe.

Figure 2 is another construction of the invention applied to the induction pipe.

Figure 3 is a further construction of the ini0 nected tothecontrolling rod. The induction g0 pipe 6 is connected by a pipe l to the inner chamber 8 of the governor casing ti, whilst the other chamber 9 in the governor casing is connected to the atmosphere. A helical spring it acts on the governing'piston in the chamber 8, and tends to push it towards the leit in opposi= tion to the vacuum emsting in the induction pipe and in the chamber when the engine is running, whereby it tends to adjust the controlling rod to the-full delivery amount. To limit so the stroke of the governing piston, a stop it is provided, on which the said piston strikes in the stop position. By adjusting the throttle valve E2 in the induction pipe d, the pressure conditions existing in the induction pipe behind the throttle valve can be alterecLand thus the position of the'governing-piston uenced.

In the wall of the pipe two openings i8, 84 are arranged before and after the closing posttion of the throttle valve 52, which openings 40 are connected together by a branch pipe iii. In

this pipe 85 a valve is is pivotally arranged,

whichopens towards the space behind the throttle valve 52 in the direction of air flow in the induction pipe. (line end of a helical spring i1 is fastened to the valve 16, and-its other end connected to the wall of the pipe i5. 7

When the separate suction strokes of the engine pistons make themselves perceptible in the induction pipe when the throttle valve is partly closed, this leads to sudden variations of the pneumatic head of pressure utilised as the governing force. By these suction strokes the governing piston is suddenly drawn further in the "stop direction and the governor 'spg com as the engine. The additional valve IS in the branch pipe counteracts the formation of these oscillations of the governing members in such a way that on a suction stroke taking place which, owing to the position of throttle valve, cannot at once cause a suificient supply of air from the space in advance-of the throttle valve it opens the branch pipe so that additional air can pass into the space behind the throttle valve by bypassing the throttle valve, and quickly qualise the fluctuation in pressure. When the throttle valve is fully closed, the additional valve will correspondingly open. further than on a slight opening of the throttle valve. After equalization of the pressure fluctuation, which thus can only act weakly on the governing members, the valve in the branch pipe is again closed by the spring, which is stretched when the valve opens.

Continuously greater pressure variations also occur in the induction pipe when the throttle valve is suddenly closed during rapid running of the engine, so that the governing members execute great governing movements. In this case, also, the apparatus according to the invention prevents the irregular supply of fuel amounts to the engine. In particular, however, the idling speed may vary within such great limits that the machine stops automatically. By means of the simple arrangement according to the invention the idling speed can be approximated quite closely to that speed at which the engine can still just be kept running.

In the construction according to Figure 2, an opening I8 is provided in the wall of the induction pipe behind the Venturi tube l9,'and is kept closed by a spring-loaded valve 20. Only when the fluctuations in the vacuum exceed a predetermined degree does the valve 20 open, so that the variations in vacuum" are quickly equale ised.

The same applies to the case shown in Fig. 3, where an opening 2| is arranged in the disc of the throttle valve I2 itself. Here also the valve 22 is held closedby a spring 23 until a fluctuation in pressure automatically opens the valve,

so that the current of airflowing' through causes an equalisation'of the fluctuations.

I declare that what I claim is:

1. In an injection internal combustion engine including an induction pipe, a resiliently loaded differential pressure governor adapted to vary the quantity of fuel injected in dependence upon the pressure conditions in the induction pipe, 2. throttle member in said induction pipe and a duct connected with the governor and opening into said induction pipebetween said throttle member and the engine, air supply means opening into said induction pipe between the throttle member and the engine, and a resiliently-loaded valve controlling said air supply means and tensioned to open when a predetermined degree of suction is reached in said induction pipe to maintain the suction therein substantially at a mean value compatiblewith the predetermined speed,

thereby eliminating pressure fluctuation at low engine speeds which otherwise would tend to oscillate the governor.

2. In an injection internal combustion engine including an induction pipe, a resiliently loaded difierential pressure governor adapted to vary the quantity of fuel injected in dependence upon the pressure conditions in the induction pipe, a

"throttle member in said induction pipe and a duct connected with the governor and opening into said induction pipe between said throttle member and the engine, and valve means responsive to the suction in said induction pipe and operable when the suction in said pipe between the engine and the throttle member reaches a predetermined degree .to supply air to said induction pipe between the throttle member and the engine to maintain the suction in said induction pipe at a mean value compatible with the predetermined speed of the engine and thus prevent-tendency of oscillation of the governor.

3'. In an injection internal combustion engine including an induction pipe, a resiliently loaded differential pressure governor adapted to vary the quantity of fuel injected in dependence upon the pressure conditions in the induction pipe, a throttle member in said induction pipe and a duct connected with the governor and opening into said induction pipe between said throttle member and the engine, and means including an air inlet in said induction pipe between the throttle member and the engine and a springloaded valve controlling said inlet, said valve being responsive to the suction in said induction pipe and arranged to open when a predetermined degree of suction is reached in said induction pipe to maintain the suction therein sub stantially at a mean value compatible with the predetermined speed of the engine.

4. In an injection internal combustion engine including an induction pipe, a resiliently loaded difierential pressure governor adapted to vary the quantity of fuel injected in dependence upon the pressure conditions in the induction pipe, a voluntarily adjusted throttle member in said induction pipe and a duct connected with the governor and opening into said induction pipe between said throttle member and the engine, a by-pass in said induction pipe extending to opposite sides of. said throttle member when closed for the supply of additional air, and a springloaded valve controlling said by-pass and tensioned to open when a predetermined degree of suction is reached in said induction pipe to maintain the suction in said induction pipe at a mean value compatible with the predetermined speed of the engine.

5. In an injection internal combustion engine including an induction pipe, a resiliently loaded differential pressure governor adapted to vary the quantity of fuel injected in dependence upon the pressure conditions in the induction pipe, a throttle member in said induction pipe and a duct connected with the governor and opening into said induction pipebetween said throttle termined degree of suction is reached in said induction pipe to maintain the suction in said induction pipe at a mean value compatible with the predetermined speed of the engine.

6. In an injection internal combustion engine including an induction pipe, a resiliently loaded differential pressure governor adapted to vary the quantity of fuel injected in dependence upon the pressure conditions in the induction pipe, a

age ioo throttle member in said induction. pipe and a duct connected with the governor and opening into said induction pipe between said throttle member and *the engine, said throttle member being provided with an opening, and a one-way spring-loaded valve carried by said throttle mem her and controlling said opening, said valve be- 7 ing tensioned to open in the direction of the air supply to said engine when a predetermined degree of suction is reached in said induction pipe to maintain the suction insaid induction pipe at a mean value compatible with the predetermined speed of the engine. I ,1

7. In an injection internal combustion engine including an induction pipe, at resiliently loaded difi'erential pressure governor adapted to vary the quantity of fuel injected in dependence upon the pressure conditions. in the induction pipe, a

absolute pressure space, the resiliently-loaded valve means being arranged and tensioned in such a manner that it opens when a predetermined degree of auction in said part 01 the induction pipe has been reached to supply air, and thereby maintain the suction in said induction pipe substantially at a mean valuecompatible with a predetermined speed 01' the engine, thereby eliminating pressure fluctuation at low engine speeds which otherwise would tend to oscillate the governor. 7

V 8. In an injection internal combustion engine including an induction pipe, a resiliently loaded difierential pressure governor adapted to vary the quantity of fuel injected in dependence upon the pressure conditions in the induction pipe, a

voluntarily adjusted throttle member in said induction pipe and a duct connected with the governor and opening into said induction pipe between said throttle member and the engine, an

air supply passage opening into said induction pipe and extending to opposite sides of said throttle member when closed, and a loaded oneway valve controlling said passage and arranged to open when a predetermined degree of suction is reached in said induction pipe to maintain the suction in said induction pipe at a mean value compatible with the predeteed speed. 

